They warned Berk not to open that trap door...
Admiral Ackbar knew about it all along!
In tribute to Tim Rose, who played Ackbar, and Terry Brian, who animated Trap Door - and who both sadly passed away in 2016.

Under Old English law, which has sadly been removed decades ago any one who touched the sanctuary knocker or hagoday, on the Cathedral door at Durham or other places around Englash, would have the right to asylum.